Tim Berners-Lee wrote:
>
> No, there *is* something fundamentally different between most distributed OO
> systems and frame systems and RDF. In a frma system, fundamentally, the
> designer of an object class defines the set of properties an object may
> "have". This doesn't scale, as it doesn't allow anyone to say anything
> about anything: you can only say what the class designer said you could say,
> and in some syetms you can only say it if you have write access to the
> object. The RDF model in which properties are essentailly first class
> objects independent of classes (though constrains can later be expressed) is
> fundamentally more weblike, and therefore scalable.
I claim that you still could say anything about anything if
properties were local to classes in RDF: An instance
can have several different types in RDF. You would just need
to design a custom class containing the properties you wish,
and add the new class to the types of the instance you
describe.
So making properties local to classes would not hurt
scalability, but simplify migration from standard OO
systems and simplify building user interfaces since
properties could be grouped sensefully by type (a
propery normally does not come along alone, e.g.
length and width...). Writing RDF schemas would be
simplified by far for people used to OOP. Storing RDF
in database tables would be simplified since you could
build one table for each type containing the corresponding
attributes.
Best regards,
Stefan
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